Comparison of promontory and cochlear implants within a single subject.
Audiometric pure tone, speech, and psychoacoustic data were obtained from a patient who had worn a promontory electrode for two years. Subsequently the promontory implant was replaced by a scala tympani electrode (cochlear implant) and testing was repeated. Warbled tone thresholds ranged from 52-68 dB SPL for the octave frequencies 250-8000 Hz with the cochlear implant (CI), and from 65-74 dB SPL with the promontory electrode (PE). Speech discrimination scores were better with the CI than with the PE, although performance on an environmental sounds test was slightly better with the PE. Smaller intensity difference limens (DLs) were obtained with the CI (1 dB) than with the PE (about 4 dB). Frequency discrimination was poor with both electrode systems. The CI provided better frequency DLs at 250, 500, and 1000 Hz; the PE produced better DLs at 2000 Hz. When the CI was combined with a hearing aid worn on the better implanted ear, performance improved over that with either prosthesis alone.
D000368:Aged; D001301:Audiometry, Pure-Tone; D001307:Auditory Perception; D003054:Cochlear Implants; D004558:Electric Stimulation / Q000295:instrumentation*; D006310:Hearing Aids; D006320:Hearing Tests / Q000379:methods*; D006801:Humans; D008144:Loudness Perception; D008297:Male; D013063:Speech Discrimination Tests